The waters of Lake Erie seem to glow green in this image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on September 26, 2013. The color comes from an algae bloom that has been growing in the lake since July. The bloom is microcystis, a form of blue-green algae that produce liver toxins, causing numbness, nausea, vomiting, and (rarely) liver failure.